On street-unmetered parking? The City has 1100 miles of street . (I think this excludes state and county roads, I am not sure about park roads, but this is most of them). My guess is 200 spaces per mile (@ ~26 feet per car). If there were no “no parking restrictions” this gives 220,000 on-street spaces (The vast majority of which are unmetered).

Off-street private parking. There are 155,155 households. If each one has 1 off-street space (some have 2 or 3, some have 0), that would be 155,155 off-street spaces in residential areas. I would guess based on national data about twice as many in commercial areas. Roughly every car has to have a space at home, work, and shop.